2-acetoxy-4-oxa-alkanesulfonates,synthetic latices and method of preparing same

ABSTRACT

Compounds useful as surfactant compounds, 2-acetoxy-4-oxaalkanesulfonates, are disclosed. The compounds, their method of preparation and use as detergents and emulsifiers are described. The compounds are particularly suited as emulsion polymerization surfactants in the emulsion polymerization of synthetic latices from vinylic monomers. The resulting latices are characterized by being low-foaming or non-foaming and find application in the preparation of adhesives foams, polishes, coatings and the like.

United States Patent Logan [4 1 May 23, 1972 2-ACETOXY-4-OXA-ALKANESULFONATES, SYNTHETIC LATICES AND METHOD OF PREPARING SAME Ted J.Logan, Colerain Twp., Hamilton, Ohio The Procter & Gamble Company,Cincinnati, Ohio Feb. 2, 1971 Inventor:

Assignee:

Filed:

Appl. No.:

Related U.S. Application Data Division of Ser. No. 809,048, Mar. 20,1969, abancloned.

U.S. Cl ..260/29.7 SQ, 260/29.6 Z, 260/29.6 E, 260/29.6 MQ, 260/29.7 R,260/513 R [51] Int. Cl. ..C08d 7/18, C07c 143/02 [58] field ofSearch..260/29.6 2, 29.6 E, 29.6 MQ, 260/29.7 SQ, 29.7 NO, 513 R, 53l, 535,538, 557

Primary Examiner-Morris Liebman Assistant Examinzr-T. DeBenedictis, Sr.Attorney-Richard C. Witte and Ronald L. Hemingway ABSTRACT 8 Claims, NoDrawings 2-ACETOXY-4-OXA-ALKANESULFONATES, SYNTHETIC LATICES AND METHODOF PREPARING SAME This is a divisional of copending application Ser. No.809,048, filed Mar. 20, 1969 and now abandoned.

This invention relates to 2-acetoxy-4-oxa-alkanesulfonates and their useas surfactant compounds. More particularly, it relates to2-acetoxy-4-oxa-alkanesulfonates, their use as polymerizationsurfactants in the preparation of synthetic latices from vinylicmonomers by aqueous emulsion polymerization and to methods of preparingsynthetic latices.

Synthetic latices prepared by aqueous emulsion polymerization ofmonomers are well known and have become important in the preparation ofadhesives, floor polishes, foams, synthetic rubbers and in theformulation of paints and coatings for textiles, leather, paper and thelike. Synthetic latices suitable for such applications must becharacterized by a balance of desirable properties.

Synthetic latices adaptable to application in the coating arts, forexample, must be of controlled particle size and viscosity and mustexhibit low-foaming properties. In addition, they should have highsurface tension, superior chemical and mechanical stability, heatstability, freeze-thaw stability and pigment compatibility. Coatingsprepared by the curing of such latices must be water and heat resistantand have adequate tensile strength, plasticization properties, clarity,grain, luster and smoothness.

Numerous attempts have been made in the prior art to formulate laticesby emulsion polymerization from vinylic monomers having one or more ofthe aforementioned properties. A common approach to the preparation ofsuch latices has been the employment of emulsifying agents which permitthe production of latices exhibiting as great a number of theaforementioned properties as possible. While numerous emulsifying agentshave been developed, serious deficiencies still exist, particularly withregard to the property of foaming. There has been a need for a class ofemulsifying agents capable of exhibiting a balance of desirableproperties including those of low-foaming tendency.

The tendency of latices to be either non-foaming or lowfoaming is adesirable property which facilitates latex processing procedures andaids materially in the formation of high quality films or coatings. Thisproperty is especially advantageous in that it facilitates the formationof films which are substantially homogeneous and free of air bubbles andimperfections.

Excessive foaming during the processing and handling of latices isparticularly bothersome in that it results in a loss of effective use ofreaction vessels and containers. Latices exhibiting high foam levelsrequire the use of larger reaction vessels than low-foaming latices forthe processing of the same amount of latex. Similarly, the filling oftanks and drums is hampered by the propensity of latices to foamexcessively.

The tendency of latices to foam or bubble during their application tosubstrates in the form of protective coatings results in a lower overallquality of coating than is generally desirable. Foaming or bubblinglatices upon application to various materials such as wood, paper, metalor the like result in the production of non-uniform films owing largelyto the formation of air bubbles of varying dimensions the formation ofwhich results in the finished film having minute imperfectionscontributing to an overall generally undesirable appearance.

The propensity of latices to foam during preparation and application hasresulted in the employment of antifoamants and/or defoamers in anattempt to facilitate the efficient processing and handling of laticesand to improve the quality of coatings obtainable therefrom. The use ofantifoamants to effectively minimize the formation of foam is subject tocertain limitations, not the least of which is the tendency of manyantifoamants to minimize foam formation at the expense of otherdesirable properties, e.g., water sensitivity and compatibility. Thus,there has been a need for emulsion polymerization surfactants capable ofproducing latices of superior properties.

It is an object of the present invention to provide emulsionpolymerization surfactants suitable for the production of syntheticlatices.

It is a further object of the present invention to provide emulsionpolymerization surfactants suitable for the preparation of low-foamingor non-forming synthetic latices from vinylic monomers.

it is another object of the present invention to provide lowfoaming ornon-foaming synthetic latices in the process for preparing same fromvinylic monomers.

Other objects will become apparent from the consideration of theinvention described in greater detail hereinafter.

SUMMARY OF THE INVENTION This invention is based on the discovery that2-acetoxy-4- oxa-alkanesulfonates are especially suited as emulsionpolymerization surfactants in the preparation of low-foaming andnon-foaming synthetic latices from vinylic monomers. The invention thusinvolves the 2-acetoxy-4-oxa-alkanesulfonates per se and syntheticlatices containing the same. In its method aspect, the inventioncomprises polymerizing at least one vinylic monomer in an aqueous mediumin the presence of an amount effective for emulsion polymerization of a2- acetoxy-4-oxa-alkanesulfonate polymerization surfactant.

The 2-acetoxy-4oxa-alkanesulfonates of the present invention arecharacterized by the following formula ll 0 C C H: Ro-am-ti 11-0 msogo Mwherein R is alkyl of from about 10 to about 22 carbon atoms and M is asalt forming radical. These compounds are referred to herein as2-acetoxy-4-oxa-alkanesulfonates, the recitation 4-oxa referring to thepresence of an ether oxygen as the fourth atom of an otherwise alkanechain.

As will be noted from the above-described structural formula, thepolymerization surfactants utilizable herein are characterized by thepresence of an anionic sulfonate moiety, a longchain hydrophobic groupinterrupted by the presence of an oxygen ether atom and an acetoxygroup, the acetoxy group being attached to a carbon atom betato theterminal sulfonate moiety. While the precise theory or mechanismaccording to which the surfactants of the present invention function toprovide low-foaming synthetic latices is not completely understood, itis believed that the steric effect of the acetoxy group on the closepacking of surfactant molecules is involved. It is also believed thatthe solubility of the 2-acetoxy-4- oxa-alkanesulfonates of the presentinvention in organic substances such as the vinylic monomers definedhereinafter is also a factor.

The tendency of the polymerization surfactants of the present inventionto provide synthetic latices having lowfoaming characteristics isbelieved to be a function both of the length of the hydrophobic moietyand the presence of the acetoxy group. When R in the above-describedformula is alkyl of less than about 10 the low-foaming properties arenot observed. When R is greater than about 22 the diminished solubilityof the compounds in water reduces the efficiency of the polymerizationreaction. Similarly, the preparation of lowfoaming synthetic latices isnot attained when alkanesulfonates not having a 2-acetoxy group areemployed in the practice of the present invention. Preferred2-acetoxy-4-oxaalkanesulfonates are those corresponding to thehereinbefore described formula, wherein R is an alkyl group of about 12to about 18 carbon atoms. These 2-acetoxy-4-oxa-alkanesulfonates arepreferred from the standpoint of effectiveness in supporting low-foamingpolymerization reactions.

The salt-forming radical M* of the hereinbefore described structuralformula can be, for example, an alkali metal cation (e.g., sodium,potassium, lithium), ammonium or a substituted-ammonium such as aquaternary ammonium cation. Specific examples of substituted-ammoniumcations include methyl-, dimethyl-, trimethyl-, tetramethyl-ammoniumcations and the like. Quaternary ammonium cations include dimethylpiperdinium cation and those derived from alkylamines such asethylamine, diethylamine, triethylamine, mixtures thereof, and the like.The salt-forming radical serves to disperse the emulsion polymerizationsurfactant in the aqueous phase of the emulsion polymerization mixture.The salt-forming radical can be varied for compatibility with thepolymerizable monomers, polymerization catalyst, pH and other additives.Preferred cations include sodium, potassium, lithium and ammonium forreasons that involve production and use of the surfactant.

The 2-acetoxy-4-oxa-alkanesulfonates of the present invention can beprepared by a process which involves acetylation of alkyl glycerylsulfonates according to the following scheme:

6 G Acetylation ROCH2(IIHCHzSO2O )i where R and M are as hereinbeforedescribed.

The alkyl glyceryl sulfonates which are characterized by the presence ofa hydroxy group on the carbon atom adjacent to the carbon atomcontaining the sulfonate moiety are known compounds which can beacetylated in a known manner. For example, the alkyl glyceryl sulfonatescan be acetylated by reaction with acetic anhydride and pyridine or withketene, acetyl chloride or isopropenyl acetate. The reaction temperaturewill depend upon the particular acetylating agent employed and thedesired reaction time and can range from about to about 100 C. Theacetylation reaction can be conducted at atmospheric pressure or underreduced or super atmospheric conditions of pressure. The molar ratio ofalkyl glyceryl sulfonate and acetylating agent can range from a slightmolar deficiency of the acetylating agent to an excess of acetylatingagent with respect to the amount of alkyl glyceryl sulfonate employed.Suitable molar ratios of acetylating agent to alkyl glyceryl sulfonateare from about 0.8:1 to about 1021 A preferred ratio is from about 1:1to about 3: l a slight molar excess of acetylating agent beingespecially suitable. The reaction time will depend upon the reactiontemperature and type of acetylating agent employed. While best resultsare achieved at higher temperatures in a short period of time, thereaction time can vary from about 1 to about 12 hours.

Catalysts can be employed in the conduct of the acetylating reaction.Suitable catalysts include pyridine and trimethylamine and are employeddepending on the nature of the acetylating agent which is utilized.

A preferred process for preparing the compounds of the present inventioncomprises reacting an alkyl glyceryl sulfonate salt, preferably analkali metal salt, with isopropenyl acetate at a temperature of about 0to about 75 C isopropenyl acetate is a preferred acetylating agentherein from the standpoint of facility of reaction, and ease in removingthe acetone co-product from the desired product by evaporation or othersuitable methods.

The alkyl glyceryl sulfonates employed as the starting materials in thereaction with acetylating agent to produce the acetylated derivatives ofthe present invention are known compounds and are described, forexample, in U.S. Pat. No. 3,024,273 (Mar. 6, 1962) incorporated hereinby reference. These alkyl glyceryl sulfonates can be prepared byreaction of an alcohol of from about to about 22 carbon atoms andepichlorohydrin followed by reaction with an alkali metal sulfite. Thealcohols employed in the reaction with epi-chlorohydrin are those havingfrom about 10 to about 22 carbon atoms and include the middle-cutcoconut fatty alcohols, and the fatty alcohols derived fromunhydrogenated tallow. When these alcohols are employed, the resultingglyceryl sulfonates will include alkenyl glyceryl sulfonates reflectingthe presence of unsaturation in the alcohols employed. Consequently, theterm alkyl as employed herein is to be understood to include within itsscope the alkenyls as well as the true alkyls. Palm oil, hydrogenatedmarine oil, the latter containing some fatty acids having 20 to 22carbon atoms in the alkyl chain, and oxo alcohols, made by reactingcarbon monoxide and hydrogen with olefins, also represent availablefatty alcohol sources which can be employed in the preparation ofsuitable alkyl glyceryl sulfonate starting materials.

An alternative method of preparing the alkyl glyceryl sulfonate startingmaterials described herein involves reaction of an alkali metal sulfitewith an alkyl ether of glycidol wherein the alkyl has from about 10 toabout 22 carbon atoms. The reaction of alkali metal sulfites withepoxides such as alkyl ethers of glycidol is known and is described, forexample, in U.S. Pat. No. 2,925,316 (Feb. 16, 1960). This patent ishereby incorporated by reference.

Depending upon the process by which such starting materials are preparedthey will contain, in addition to the monoglyceryl ether described,certain dimeric and trimeric products. For example, the use of an excessof epichlorohydrin in the reaction with alcohol in accordance with theprocess disclosed in U.S. Pat. No. 3,024,273 will result in theproduction of chloroglyceryl ethers in which the glyceryl radical isreplaced in part with polyglyceryl radicals, e. g., with two or threecondensed glyceryl radicals. The amounts of these components in thepredominantly monoglyceryl product can be readily adjusted by regulatingthe relative proportions of epi-chlorohydrin and alcohol used to obtainthe alkyl glyceryl sulfonate mixture. If desired, the dimeric andtrimeric products can be separated by distillation. It is preferred,however, from the standpoint of convenience to employ the alkyl glycerylsulfonates of the invention in admixture with minor amounts of dimericand trimeric products, since there is no particular advantage in thepreparation and isolation of only the monoglyceryl form of said alkylglyceryl sulfonates.

Normally, the 2-acetoxy-4oxa-alkanesulfonates are prepared in the formof their sodium or potassium salts. Consequently, if it is desired tohave salts other than the sodium or potassium salts of the2-acetoxy-4-oxa-alkanesulfonates, such as the ammonium oralkylol-substituted ammonium salts, the sodium salt, for example, can bepassed over an ion exchange resin to replace the sodium ion with ahydrogen ion and the resulting acid can then be neutralized withammonia, or alkylol-substituted ammonia, e.g., the mono-, diortriethanolamines or propanolamines.

Specific examples of 2-acetoxy-4-oxa-alkanesulfonates utilizable hereinparticularly in the formation of synthetic latices characterized bylow-foaming properties include sodium2-acetoxy-4-oxa-tetradecanesulfonate; potassium 2-acetoxy-4-oxa-hexadecanesulfonate; sodium2-acetoxy'4-oxaoctadecanesulfonate; potassium2-acetoxy-4-oxa-nonadecanesulfonate; lithium2-acetoxy-4-oxa-eicosanesulfo-nate; sodium2-acetoxy-4-oxa-uncosanesulfonate; ammonium 2-acetoxy-4-oxa-docosanesulfonate; sodium2-acetoxy-4-oxatricosanesulfonate; dimethylammonium2-acetoxy-4-oxatetracosanesulfonate; potassium2-acetoxy-4-oxa-pentacosanesulfonate; dimethylpiperdinium2-acetoxy-4-oxa-hexacosanesulfonate; sodium 2-acetoxy-4oxa-eicosanesulfonate; potassium 2-acetoxy-4-oxa-docosanesulfonate;sodium 2- acetoxy-4-oxa-tetracosanesulfonate; sodium2-acetoxy-4-oxahexacosanesulfonate; and isomers thereof.

The synthetic latices of the present invention can be prepared byemulsion polymerization of vinylic monomers and mixtures of vinylicmonomers. According to the process of the present invention,homopolymers and copolymers (including terpolymers) are provided byefiecting the aqueous emulsion polymerization of one or more vinylicmonomers in the presence of an amount effective for emulsionpolymerization of a 2-acetoxy-4-oxa-alkanesulfonate hereinbefore lOl037[H24 described. As employed herein in the specification and claims, theterm vinylic monomer contemplates ethylenically unsaturatedpolymerizable monomers characterized by the presence of the group.Normally, at least one of the disconnected valences is attached to anelectroactive group, i.e., a group which substantially increases theelectrical dissymmetry or polar character of the molecule. Examples ofvinylic monomers and mixtures of monomers utilizable herein include thefollowing:

1. Styrene, chloro-substituted styrenes, and methylsubstituted styrenes,mixtures thereof, and mixtures with other monomers such as butadiene,acrylonitrile, acrylic acid, methacrylic acid and the like.

2. Vinyl chloride, vinyl acetate, and vinylidene chloride, mixturesthereof, and mixtures with other monomers such as acrylonitrile,butyraldehyde, ethylene, methyl methacrylate, butadiene, isobutylene,maleic esters such as diethyl maleate and dibutyl maleate, and the like.

. Acrylonitrile, methacrylonitrile, and mixtures thereof with butadiene,isobutylene, vinylidene chloride, chloroprene, maleic esters such asdiethyl maleate and dibutyl maleate, and the like.

4. Acrylates such as methyl acrylate, methyl methacrylate,

phenyl methacrylate, tertiary amyl methacrylate, Z-ethylhexylmethacrylate, mixtures thereof, and mixtures for example, with styrene,Z-methyl styrene, butadiene, acrylonitrile, acrylic acid, methacrylicacid, and vinyl acetate.

5. Butadienes, particularly, the 1,3-butadienes such as 2-methyl-l,3-butadiene (isoprene); piperylene; 2,3- dimethylbutadiene-l,3,mixtures thereof, and mixtures with styrene, 2-methyl styrene,acrylonitrile, methyl methacrylate, ethyl acrylate, vinyl naphthalene,methacrylamide, vinylidene chloride, methyl vinyl ether, methyl vinylketone, acrylic acid, methacrylic acid and the like.

6. Chloroprene and other 2-halo-butadienes, such as the analogs andhomologues of chloroprene; 2,3-dichloro- 1,3-butadiene; mixturesthereof, and mixtures with styrene, acrylonitrile, and the like.

Particularly preferred monomers or monomer mixtures are vinyl acetate,vinyl chloride, butadiene-styrene, and the acrylics, particularlymixtures with vinyl acetate such as vinyl acetateethyl acrylate, vinylacetate-Z-ethyl hexyl acrylate, vinyl acetate-dibutyl maleate, vinylacetate-acrylate esteracrylic acid, vinyl acetate-acrylateester-methacrylic acid, vinyl acetate-acrylate ester-itaconic acid,vinyl acetateacrylamide, and vinyl acetate-methylol acrylamide; thesebeing preferred by reason of their adaptability to a variety of coatingand adhesive applications.

It will, of course, be appreciated that the aforedescribed monomers andmixtures of monomers are described by way of example only and representthose materials which are generally known and available and whichundergo emulsion polymerization. Likewise other vinylic monomers otherthan those specifically enumerated can be polymerized in the presence ofa 2-acetoxy-4-oxa-alkanesulfonate polymerization surfactant to providesynthetic latices having low-forming properties.

The production of synthetic latices in accordance with the presentinvention is effected by polymerizing a vinylic monomer or mixture ofmonomers in an aqueous medium in accordance with polymerization methodsknown in the art. The monomer or monomers utilizable herein can bepolymerized by forming an aqueous emulsion of the vinylic monomer ormixture of monomers and 2-acetoxy-4-oxa-alkanesulfonate and initiatingpolymerization with a polymerization initiator ofthe conventionalfree-radical-forming type. While the polymerization reaction can beeffected in accordance with a batch technique whereby a premixedemulsion of monomer or mixture of monomers of the oil-in-water type ispolymerized with a polymerization initiator, the polymerization reactioncan also be effected by the continuous or delayed addition of monomer ormonomers to an initiated system.

The emulsion polymerization of the present invention can be conductedover a wide range of temperatures depending upon the particular monomersbeing polymerized. Suitable temperatures for efiecting thepolymerization range from about 10 C. to about 180 C. Preferably, thepolymerization is conducted at a temperature of about 25 C. to about C.In the case of the homopolymerization of styrene, for example, thepolymerization reaction is conducted at a temperature of about 25 C toabout 70 C The amount of 2-acetoxy-4- oxa-alkanesulfonate surfactantemployed herein in the preparation of emulsions polymerizable to formsynthetic latices of the hereinbefore described type varies with thenature of monomer or monomers employed in the polymerization. A smallamount sufficient to form an aqueous emulsion of polymerizable monomers,and corresponding to about 0.5 to 5 percent by weight of the monomer ormixture of monomers employed, can be utilized herein. Preferably, anamount of about 0.7 to about 2.5 percent of the 2-acetoxy 4-oxa-alkanesulfonate is employed.

The relative proportions of co-monomers employed in the preparation ofcopolymers will vary depending upon the particular properties desired inthe polymer. The 2-acetoxy-4- oxa-alkanesulfonates of the inventionpermit the preparation by emulsion polymerization of a wide range ofproducts as to composition and properties with a correspondingly widerange of end uses. In the preparation of styrene-butadiene laticessuitable for the preparation of latex paints, for example, a ratio inparts by weight of styrene to butadiene of about 0.8:1 to about 4:1, andpreferably about 1.5:1 to about 3:1 is employed. Similarly, emulsionpolymerization of a mixture of about 0.25:1 to about 5:1, respectively,of lower alkyl acrylates, e.g. butyl acrylate and lower alkylmethacrylates, e.g. methyl methacrylate, provide latices adapted to usein the preparation of water-based adhesives, foamed carpet backings,water-based latex paint formulations and the like.

The amount of water employed in the emulsion polymerization processherein varies with the solids content desired for the final latex andcan be varied to provide latices ranging from liquid to salve-like orgel consistency. Preferably, about 30 to about 400 parts of water byweight are used per 100 parts of monomer mixture. The resulting laticesare aqueous compositions having solids contents of from about 20 percentto about 75 percent.

The polymerization reaction can be conducted in a reaction vesselprovided with stirring means and an external means of supplying orremoving heat. Normally, the polymerization is conducted by charging aninitially prepared monomeric emulsion to the reaction vessel and raisingthe temperature, adding a polymerization initiator with stirring andallowing the reaction to continue until substantial conversion ofmonomer to polymeric latex has taken place. In accordance with thepresent invention, the employment of a 2-acetoxy-4-oxa-alkanesulfonatefacilitates the efficient processing of latex in that the level of foamresulting from agitation is minimized and the reactive capacity of thereaction vessel employed is maximized. The presence of2-acetoxy-4-oxa-alkanesulfonate as an integral part of the latexparticles serves also to minimize foam formation subsequent tocompletion of polymerization, i.e., during subsequent agitation,shaking, pumping, application to a substrate or the like.

Suitable polymerization initiators or catalysts include conventionalfree radical-generating initiators such as the per compounds. Examplesinclude inorganic and organic peroxides and per-salts such as benzoylperoxide, benzoyl acetyl peroxide, lauryl peroxide, tertiary butylperbenzoate, peracetic acid, acetyl peroxide, hydrogen peroxide,tertiary butyl hydroperoxide, sodium peroxide, barium peroxide,

potassium persulfate, percarbonate or perborate. Two or more suchinitiators can be employed if desired. When the polymerization isconducted at temperatures below reflux, initiators of the redox type canbe used, e.g., potassium persulfate with sodium bisulfite, hydrogenperoxide with ferrous sulfate, hydrogen peroxide with ferric sulfate andsodium pyrophosphate. Certain azo derivatives, e.g.,2,2-azodiisobutyronitrile are also useful. The initiator should beemployed in an amount of about 0.01 to 1.0 percent by weight of themonomer or mixture of monomers employed in the polymerization reaction.

The range of pH of the emulsion polymerized in accordance with thepresent invention can be regulated with the aid of a buffering agent.Normally, the polymerization reactions conducted in accordance with thepresent invention are conducted at pl-ls between 2 and l l and anywater-soluble buffering agent which will maintain the pH of the emulsionwithin this range can be employed.

Typical of the buffering agents which can be employed are such compoundsas sodium carbonate, potassium carbonate, ammonium carbonate, sodiumacetate, potassium acetate, sodium bicarbonate, sodium phosphate,potassium phosphate, ammonium phosphate, sodium tetraborate, potassiumtetraborate and the like. These compounds can be employed individuallyor in combination.

ln like manner, any of the conventional regulators (e.g., diisopropylxanthate, octylmercaptan), stabilizers (e.g., gelatin, carboxymethylcellulose), activators (e.g., ferrous ion and AgHSO NaHSO or Na S,O.,),electrolytes (e.g., KCl, KNO or the like can be employed herein toadvantage.

The synthetic latices prepared according to the present invention arecharacterized herein as being non-foaming or lowfoaming. The foamingpropensities of synthetic latices can be determined conveniently by anumber of methods. A simple method of determining relative degrees offoaming involves visual observation of a latex subsequent to vigorousshaking. Another suitable means involves mechanical stirring of thelatex and observation of increased volume. Such a method is illustratedhereinafter.

Synthetic latices prepared in accordance with the present invention arefine aqueous dispersions of polymeric particles ranging from lightviscous liquids to pasty masses of salve-like consistency dependinglargely on the amount of water employed in the polymerization reactionand the particular monomers polymerized. The polymers prepared inaccordance with the present invention can be cured or dried to formfilms making them adaptable as vehicles for coating or paintcompositions for a variety of substrates. They can be compounded withsuitable pigments, resinous materials, fillers, thickening agents,plasticizers, stabilizing agents or the like for use in theseapplications. In addition, certain of the latices herein can be employedin the preparation of floor polishes, adhesives, foamed polymericarticles, carpet backings and the like.

The 2-acetoxy-4-oxa-alkanesulfonates of the present invention inaddition to being useful as emulsion polymerization surfactants, haveexcellent wetting and cleansing properties. These compounds are readilysoluble in water and can be employed generally in situations where apowerful wetting, washing or dispersing agent is desired. For example,they can be used as detergent actives in the cleansing of textilematerials as well as hard surfaces. When so employed, they can beadmixed with any of the known inorganic or organic builder compoundsnormally employed in the detergency arts. Suitable water-solublealkaline builders include sodium tripolyphosphate and sodiumpyrophosphate. The compounds of the present invention also demonstratesolubility in organic solvents such as perchloroethylene, chloroform,ethanol and trichloroethylene. The solubility of these compounds inorganic solvents is in marked contrast to that of conventional anionicsurfactant materials. For example, the alkali metal salts ofalkylbenzene sulfonates and alkyl sulfates while excellent detergentcompounds from the standpoint of efficient soil-removal are notappreciably soluble in perchloroethylene. The solubility of the2-acetoxy-4-oxa-alkanesulfonates herein in the organic solvents of thehereinbefore classes renders them of special value in the formulation oforganic dry-cleaning compositions.

Suitable organic dry-cleaning compositions contain a major amount, fromabout to about 98 percent of an organic solvent such as carbontetrachloride, trichloroethylene, perchloro-ethylene and Stoddardsolvent, and from about 0.2 percent to about 5 percent, and preferably0.25 to 1 percent, of a 2-acetoxy-4-oxa-alkanesulfonate of theinvention.

The following examples are given in illustration and are not intended aslimitations on the scope of this invention. Where parts are mentioned,they are parts by weight.

EXAMPLE I Into a 2-liter, three-necked, round bottom flask was placed g.of coconut-tallow alkyl glyceryl sulfonate of the formula (R beingderived from an admixture of coconut and tallow alcohol having a chainlength distribution of C to about C 1,500 g. of isopropenyl acetate, and15 g. of p-toluene sulfonate acid. The contents of the reaction flaskwere refluxed (92 C.) for 5 hours. The solution was cooled to 10 C. andthe precipitated solid was filtered and boiled in 800 ml. of refluxingacetone. The solution was cooled to 5 C. and filtered in a dry box togive 133 g. of product. Infrared analysis identified the product assodium 2-acetoxy-4-oxa-coconut-tallow-alkanesulfonate, indicatingconversion of hydroxy to acetoxy groups.

Substantially similar results are obtained when the mixed coconut-tallowalkyl glyceryl sulfonate is replaced with the following alkyl glycerylsulfonates in that the 2-hydroxy group is replaced by an acetoxy group:the sodium salt of tallowalkyl glyceryl sulfonate; the potassium salt ofcoconut-alkyl glyceryl sulfonate.

Substantially similar results can be obtained when the isopropenylacetate employed in the above example is replaced with the followingacetylating agents, in that acetylation of the hydroxy group takesplace: acetyl chloride, ketene or acetic anhydride.

EXAMPLE ll Into a l2-liter flask equipped with a reflux condenser andthermometer were added 700 g. of sodium2-hydroxy-4-oxadocosanesulfonate, C, H OCl-I CH(OH)CH SO Na, 7 liters ofisopropenyl acetate and 28 ml. of concentrated sulfuric acid. Thecontents of the reaction vessel were heated to reflux temperature andallowed to reflux for four hours. The reflux reaction product was cooledand precipitation of crystals was observed. The precipitated product wasfiltered, washed with acetone, and dried. infrared analysis identifiedthe product as sodium 2-acetoxy-4-oxa-docosane-sulfonate and indicatedan absence of hydroxyl bonds, i.e., conversion of the hydroxy groups toacetoxy groups.

Substantially similar results can be obtained when the following2-hydroxy-4-oxa-alkanesulfonate salts are employed in place of sodium2-hydroxy-4-oxa-docosanesulfonate in that the corresponding Z-acetoxyderivatives are obtained: sodium 2-hydroxy-4-oxa-tetradecanesulfonate;potassium 2-hydroxy- 4-oxa-hexadecanesulfonate; sodiumZ-hydroxy-A-oxa-octadecanesulfonate; potassium2-hydroXy-4-oxa-nonadecanesulfonate; lithium2-hydroxy-4-oxa-eicosanesulfonate; sodium2-hydroxy-4-oxa-uncosanesulfonate; ammonium 2-hydroxy-4-oxa-docosanesulfonate; sodium 2-hydroxy-4-oxa-tricosanesul- EXAMPLE IllTo 642 g. (1.7 moles) of sodium 2-hydroxy-4-oxa-eicosanesulfonate wasadded 5 liters of isopropenyl acetate (solvent and reactant) and ml. ofconcentrated sulfuric acid (catalyst) in a three-necked, l2-liter,round-bottom flask equipped with a reflux condenser, mechanical stirrerand thermometer. The resulting heterogeneous mixture was heated toreflux (80 C. to 90 C.) for 5 hours, during which time the mixturebecame homogeneous and slightly brown in color. Upon cooling, theproduct precipitated from solution, and was then filtered, washedseveral times with acetone, and allowed to dry in air. The total of 515g. (68 percent yield) of product resulted. Infrared analysis showed thatthe hydroxyl group of the starting material had been converted to thedesired acetoxy group, i.e., that the desired product2-acetoxy-4-oxaeicosanesulfonate was obtained.

EXAMPLE IV A stable, low-foaming latex was prepared from the followingingredients, the emulsion polymerization surfactant being that ofExample lII:

A monomer emulsion was prepared by admixing 85 parts of the ionizedwater, 60 parts butyl acrylate, 40 parts methyl methacrylate, 0.2 partsK 8 0, and 6 parts sodium Z-acetoxy- 4-oxaeicosanesulfonate. To a 500ml. three-necked flask equipped with a reflux condenser, thermometer andstirring means, was added 21 parts of water and an equivolume amount ofthe prepared emulsion. The contents of the reaction vessel were heatedin a water bath and refluxing began at a temperature of 82 C., thetemperature rising to 90 C. in about 8 minutes. When the refluxingsubsided the remaining amount of monomer emulsion was added slowly overa period of 1.5 hours with refluxing at a temperature of 8894 C. Uponcompletion of the addition of monomer emulsion the temperature wasraised to 97 C. to complete polymerization. The reaction vessel wascooled to room temperature with stirring and the contents were strainedthrough a lOO-mesh wire screen. The latex which comprised 47.8 percentsolids had a viscosity at C. of 1590 centipoises at a pH of4.0. Thelatex was evaluated for reactor coagulum and mechanical stabilityaccording to the hereinafter described tests. Reactor coagulum was lessthan 0.1 percent and coagulum after testing for mechanical stability wasabout 1 percent. The latex did not foam upon vigorous shaking.

Substantially similar results can be obtained when the followingemulsion polymerization surfactants are employed in place of all or partof the sodium 2-acetoxy-4-oxa-eicosanesulfonate, in that low-foaminglatices are obtained: sodium 2- acetoxy-4-oxa-tetradecanesulfonate;ammonium 2-acetoxy-4- oxa-pentadecanesulfonate; potassium2-acetoxy-4-oxa-hexadecanesulfonate; sodium2-acetoxy-4-oXa-heptadecanesulfonate; sodium2-acetoxy-4-oxa-octadecanesulfonate; potassium2-acetoxy-4-oxa-nonadecanesulfonate; lithium 2-acetoxy-4-oxa-eicosanesulfonate; sodium 2-acetoxy-4-oxa-uncosanesulfonate;ammonium 2-acetoxy-4-oxa-docosanesulfonate; sodium2-acetoxy-4-oxa-tricosanesulfonate;

dimethylammonium 2-acetoxy-4-oxa-tetracosanesulfonate; potassium2-acetoxy-4-oxa-pentacosanesulfonate; dimethylpiperdinium2-acetoxy-4-oxa-hexacosanesulfonate; sodium 2-acetoxy-4-oxa-docosanesulfonate; potassium 2-acetoxy-4-oxa-docosanesulfonate; sodium 2-acetoxy-4-oxa-hexacosanesulfonate; andisomers thereof.

EXAMPLE V A stable, low-foaming latex was prepared from the followingingredients employing the product of Example II as an emulsionpolymerization surfactant:

Components Parts by Weight Butyl acrylate 120 Methyl methacrylate a z a0,4 Sodium 2-acetoxy-4-oxadocosanesulfonate 10 Water 210 A monomeremulsion was prepared by admixing 168 parts of the ionized water, partsbutyl acrylate, 80 parts methyl methacrylate, 0.4 parts K S O and 10parts sodium 2-acetoxy-4-oxa-docosanesulfonate. To a SOO-ml.three-necked flask equipped with a reflux condenser, thermometer andstirring means, was added 42 parts of water and an equivolume amount ofthe prepared emulsion. The contents of the reaction vessel were heatedin a water bath and heated to reflux temperature. When the refluxingsubsided, the remaining amount of monomer emulsion was added slowly overa period of 1.5 hours with refluxing at a temperature of about 8894 C.Upon completion of the addition of monomer emulsion the temperature wasraised to complete polymerization. The reaction vessel was cooled toroom temperature with stirring and the contents were strained through aIOO-mesh wire screen. The latex which comprised 49 percent solids had aviscosity at 25 C. and a pH of 3.5 of 700 centipoises. Reactor coagulumwas less than 0.4 percent and coagulum after the mechanical stabilitytest was about 2 percent. The latex did not foam upon vigorous shaking.

Substantially similar results are obtained when the following acrylates,methacrylates, acids or mixtures thereof are polymerized in like mannerin that low-foaming latices are obtained: methyl acrylate, ethylacrylate, isobutyl methacrylate, phenyl methacrylate, tertiary amylmethacrylate, 2-ethylhexyl methacrylate, acrylic acid, methacrylic acid.

EXAMPLE VI A stable, non-foaming latex is prepared from the followingmaterials:

Components Parts by Weight Butadiene 40 Styrene 60 Sodium2-acetoxy-4-oxa-eicosanesulfonate 6 K 5 0 (as 0.17 M solution) 6 KCl (as4 M solution) 8 Water I I0 EXAMPLE VII A smooth, low-foaming, stablelatex is provided by polymerization of the following ingredients:

Component Parts by Weight Vinyl chloride 300 Potassium2-acetoxy-4-oxatetracosanesulfonate 8 K 8 2 Water 600 The polymerization(substantially 100 percent conversion) is effected by introducing thedeionized water, the potassium 2-acetoxy-4-oxa-tetracosanesulfonate andK 8 0 into a highpressure reaction vessel adapted with stirring means,sparging with nitrogen and introducing the vinyl chloride monomer. Theingredients are allowed to react in the closed reactor at a temperatureof 60 C. for 50 minutes. The reaction mass is agitated during thereaction by means of an agitator rotating at 300 rpm. Substantially nofoam is generated during the reaction. The resulting latex when agitatedby stirring or vigorous shaking is substantially non-foaming.

Substantially similar results are obtained when vinylidene chloride isemployed in lieu of vinyl chloride in that a lowfoaming, stable latex isformed.

EXAMPLE VIII A vinyl acetate fluid, low-foaming latex is prepared bypolymerization of the following ingredients:

Components Parts by Weight Vinyl acetate lOO Sodium bicarbonate (as 1%aqueous solution) 10 K 0 (as 1% aqueous solution) 30 Ammonium2'acetoxy-4-oxatricosanesulfonate 2.5 Water 100 To a suitable reactionvessel is added the ammonium 2- acetoxy-4-oxa-tricosanesulfonate, thesodium bicarbonate solution, the required amount of water and the vinylacetate.

The mixture is then purged with nitrogen below its surface for 5 tominutes. Following the purge, the potassium persulfate solution is addedand the reaction vessel is capped securely. Thereafter the vesselcontaining the reaction mixture is placed in rotating holders in a waterbath heated to 52 C. and is reacted at this temperature for to hourswhile slowly rotating the reaction vessel holders to achieve agitationof the reaction mixture. Following reaction, the reaction vessel isremoved, cooled, and the resulting polymer latex is filtered to removeany coagulum.

Substantially similar results are obtained when part of the vinylacetate is replaced with methyl methacrylate, diethyl maleate, vinylchloride or vinylidene chloride.

EXAMPLE IX A smooth, low-foaming latex is provided by polymerizing thefollowing ingredients:

Components Parts by Weight Vinyl chloride 50 lsobutylene 3 3 Water(deionized) I50 Lithium Z-acetoxy-A-oxa-hexadecanesulfonate 4 Potassiumpersulfate 0.5

The vinyl chloride and isobutylene are admixed at about 50 C., themixture is added to a closed reactor or bomb together with the otheringredients and reacted at 60 C. for hours while being continuouslyagitated. The resulting latex has highly desirable properties.

Substantially similar results are obtained in that a stable low-foaminglatex is obtained when the following are employed in lieu ofisobutylene: acrylonitrile, methyl methacrylate, butadiene, diethylmaleate, dibutyl maleate or mixtures thereof.

EXAMPLE X A fluid, stable, low-foaming latex is prepared from thefollowing materials:

Components Parts by Weight Acrylonitrile I40 Butadiene 400 Potassium2-acetoxy-4-oxa-eieosanesulfonate l2 Hydrogen peroxide (as 15% solution)20 Water (deionized) 970 To a solution of the potassiumZ-acetoxy-4-oxa-eicosanesulfonate in water in a beverage bottle reactionvessel are added the acrylonitrile, the hydrogen peroxide and butadienein turn. The butadiene is added after capping with the aid of a syringe,the beverage bottle is sparged with nitrogen and the polymerization isconducted in the capped bottle at about 40 C. for about 15 hours withagitation. Substantially similar results can be obtained when butadieneis replaced by isobutylene or when acrylonitrile is replaced bymethacrylonitrile in that a low-foaming, stable latex is obtained.

EXAMPLE XI Chloroprene is polymerized to a stable, smooth latex from thefollowing ingredients:

Components Parts by Weight Chloroprene I00 Tertiary dodecyl mercaptan0.40 Water (deionized) I00 Ammonium 2-acetoxy-4-oxatetracosanesulfonate2.6

The chloroprene is admixed with a solution of the emulsifier andtertiary dodecyl mercaptan, the chloroprene being added gradually withactive stirring and in the absence of oxygen. The polymerization isallowed to proceed for about 20 hours in a closed reactor underconditions of cooling to maintain the temperature at about 20 C. Theresulting synthetic latex has excellent stability and fluidity andexhibits little tendency to foam upon agitation.

Substantially similar results are obtained when the following materialsare employed in place of a part of the chloroprene: styrene,acrylonitrile and methacrylonitrile.

EXAMPLE XII Vinyl acetate/Z-ethylhexyl acrylate monomers are polymerizedto a low-foaming latex from the following ingredients employing theprocedure of Example VIII:

Components Parts by Weight Vinyl acetate 90 2ethylhexyl acrylate(containing 50 ppm hydroquinone) Sodium bicarbonate (as 1% aqueoussolution) 10 Potassium persulfate (as 1% aqueous solution) 30 Potassium2acetoxy-4-oxaoctacosanesulfonate 5 Water 70 EXAMPLE XIII A low-foamingstyrene synthetic latex is prepared from the following materials:

Components Parts by Weight Styrene 135 Sodium2-acetoxy-4-oxa-eicosanesulfonate 4 Potassium persulfate 0.4 Water(deionized) 210 The emulsifier is dissolved in about 90 percent of thedeionized water and charged into a suitable reaction vessel. Thereaction vessel is brought to reaction temperature, 60 C., and thestyrene is added with agitation. A solution of potassium persulfate inthe remaining amount of water is added at a uniform rate during thefirst minutes of the polymerization. The reactor is cooled toapproximately C. and the reaction is terminated after 2 hours. A verylow order of foam formation is observed during the polymerization. Thelatex is filtered through an 80 mesh stainless steel screen to removeany coagulum from the resulting polymer. A latex produces little foamupon vigorous agitation.

Synthetic latices of 50 percent solids content were prepared from butylacrylate and methyl methacrylate according to the procedure of Example Vexcept that commercially available emulsion polymerization surfactantswere substituted for the Z-acetoxy-4-oxa-docosanesulfonate of Example V.The commercial polymerization surfactants employed were Surfactant A(sodium salts of sulfated and ethoxylated alcohols), Surfactant B(sodium salts of sulfated and ethoxylated alcohols), Surfactant C(sodium dihexyl sulfosuccinate), Surfactant D (sodium diamylsulfosuccinate), and Surfactant E (tetrasodium N-(l,2-dicarboxyethyl)-N-octadecyl sulfosuccinamate). Each surfactant wasemployed in an amount by weight of 5 parts per hundred of monomer (5phm). The resulting synthetic latices were evaluated according to thefollowing procedures and compared with the latices of Examples IV and V,the results being tabulated in Table l.

FOAMING AND MECHANICAL STABILITY TEST A 50-g. sample of 50 percent totalsolids-containing latex is placed into an approximately SOO-ml. glasscontainer. The stirred shaft to which is afiixed a small diameter diskis immersed close to the bottom of the container and mixed for minutesat a speed of about 14,000 rpm. The latex after completion of the testis filtered to collect any coagulum formed as a result of the test. Thecoagulum is rinsed gently with distilled water, dried and the amount ofcoagulum weighed.

The foaming tendency of the latex is evaluated by noting the volume oflatex and foam after the 30 minute period of agitation at 14,000 rpm ashereinbefore described and comparing this volume with the initial volumeprior to stirring. A lowfoaming synthetic latex produces a 10 percent orless increase in volume under the conditions of this test. Amedium-foaming latex produces an increase of about 50 percent, while ahigh-foaming latex produces a volume increase of about 75 percent ormore. A non-foaming latex as used herein is substantially free of foamand produces a volume increase of less than about 2 percent.

TABLE 1 Reactor Mechanical Surfactant Foaming Coagulum StabilityCoagulum formed) Example IV None 0.1 1 Example V None 0.4 2 Surfactant AHigh 1.3 18 Surfactant B Medium 3.5 5 Surfactant C High 0.3 21Surfactant D High 0.6 37 Surfactant E Medium 0.6 10 Surfactant '6 pansemulsion polymerization surfactant per hundred of monomer.

As can be determined from Table l, the latices of Examples IV and Vexhibited excellent mechanical stability and nonfoaming properties.Synthetic latices prepared from the emulsion polymerization surfactantsof the present invention exhibit a balance of desirable properties,particularly with respect to their tendencies to produce low orders offoam during polymerization and subsequent to their preparation byvigorous shaking and agitation.

EXAMPLE XIV A dry-cleaning composition suitable for the cleaning ofcotton, woolens and most synthetic textiles is prepared by dissolvingthe compound of Example I in perchloroethylene in an amount of 0.25percent by weight of the solution. This solution when agitated for 30minutes with artificially soiled swatches followed by rinsing withperchloroethylene, drying and grading for soil removal resulted in 56percent soilremoval on cotton swatches, and 65 percent soil-removal fromsoiled Dacron swatches.

Substantially similar results can be obtained when the following2-acetoxy-4-oxa-alkanesulfonates are employed in lieu of the compound ofExample XII in that efficient dry-cleaning properties are observed:sodium 2-acetoxy-4-oxatetradecanesulfonate; potassium2-acetoxy-4-oxa-hexadecanesulfonate; sodium2-acetoxy-4-oxa'octadecanesulfonate; potassium2-acetoxy-4-oxa-nonadecanesulfonate; lithium2-acetoxy-4-oxa-eicosanesulfonate; sodium Z-acetoxy-4-oxa-uncosanesulfonate; ammonium 2-acetoxy-4-oxadocosanesulfonate;sodium 2-acetoxy-4-oxa-tricosanesulfonate; dimethylammonium2-acetoxy-4-oxa-tetracosanesulfonate; potassium2-acetoxy-4-oxa-pentacosanesulfonate; dimethylpiperdinium2-acetoxy-4-oxa-hexacosanesulfonate; sodium2-acetoxy-4-oxa-eicosanesulfonate; potassium-2-acetoxy-4-oxadocosanesulfonate; sodium2-acetoxy-4-oxatetracosane-sulfonate; and isomers thereof.

EXAMPLE XV A detergent composition providing excellent cleaning formosttextile materials has the following formula:

Components Parts by Weight Sodium 2-acetoxy-4-oxa-eicosanesulfonate 17.5Sodium sulfate 23 Sodium tripolyphosphate 50 Sodium silicate 6 Water 3.5

The product of Example I likewise provides efficient cleaning propertiesand was evaluated for detergency by washing naturally soiled white dressshirts. Shirts were worn by male subjects under ordinary conditions for2 normal working days. The degree to which a detergent compositioncontaining a detergent compound to be tested cleaned the collars andcuffs of the soiled shirts, relative to the cleaning degree of a similarcomposition containing a standard detergent compound was considered ameasure of the detergency effectiveness of the test compound.

The washing solution used in the test contained 0.02 percent of theorganic surface active agent of Example I and 0.05 percent sodiumtripolyphosphate. No fluorescers or bleaches or anti-redeposition agentswere used. The pH of the washing solution was 10 and water of 5 grainsper gallon hardness was used. A conventional, agitator-type washer wasused. The detergent compounds in the standard detergent composition wassodium tallow alkyl sulfate, a commonly used organic detergent compoundin heavy-duty laundry detergent compositions. The test detergentcomposition contained the detergent compound to be tested, i.e., productof Example 1.

Under these conditions the detergency effectiveness of the product ofExample I in wash water of 80 F. was indistin guishable from that of thesodium tallow alkyl sulfate-containing standard composition. Desirablecleaning was also obtained at l30 F. Thus, the product of Example Ishows desirable levels of cleaning when employed as a detergent activein the preparation of detergent compositions.

What is claimed is:

l. A low-forming aqueous synthetic latex composition comprising apolymer of at least one vinylic monomer and an amount, sufficient toeffect emulsion polymerization of said monomer, of a2-acetoxy-4-oxa-alkanesulfonate olymerization surfactant having theformula wherein R is alkyl of about 10 to about 22 carbon atoms and M isa salt-forming radical selected from the group consisting of alkalimetal, ammonium and substituted ammonium cations.

2. The synthetic latex of claim I wherein the amount of 2-acetoxy-4-oxa-alkanesulfonate is about 0.5 to about 5 percent by weightof the vinylic monomer employed in emulsion polymerization.

3. The synthetic late): of claim 2 wherein R is alkyl of about 12 toabout 18 carbon atoms.

4. The synthetic latex of claim 3 wherein M is alkali metal.

5. The synthetic latex of claim 4 wherein the polymer is a homopolymerof styrene.

6. The synthetic latex of claim 4 wherein the polymer is a homopolymerof vinyl chloride.

7. The synthetic latex of claim 4 wherein the polymer is a copolymer ofstyrene and butadiene.

8. The synthetic latex of claim 4 wherein the polymer is a copolymer ofbutyl acrylate and methyl methacrylate.

2. The synthetic latex of claim 1 wherein the amount of2-acetoxy-4-oxa-alkanesulfonate is about 0.5 to about 5 percent byweight of the vinylic monomer employed in emulsion polymerization. 3.The synthetic latex of claim 2 wherein R is alkyl of about 12 to about18 carbon atoms.
 4. The synthetic latex of claim 3 wherein M is alkalimetal.
 5. The synthetic latex of claim 4 wherein the polymer is ahomopolymer of styrene.
 6. The synthetic latex of claim 4 wherein thepolymer is a homopolymer of vinyl chloride.
 7. The synthetic latex ofclaim 4 wherein the polymer is a copolymer of styrene and butadiene. 8.The synthetic latex of claim 4 wherein the polymer is a copolymer ofbutyl acrylate and methyl methacrylate.